PYONGYANG, North Korea - The U.S. Geological Survey recorded a small earthquake in an area of North Korea where previous nuclear tests have been carried out.

The USGS said the magnitude 2.9 quake occurred about 13 miles northeast of Sungjibaegam, North Korea.

It added that the quake was recorded "in the area of the previous North Korean Nuclear tests."

The USGS noted, “The event has earthquake like characteristics, however, we cannot conclusively confirm at this time the nature (natural or human-made) of the event. The depth is poorly constrained and has been held to 5 km (3 miles) by the seismologist."

The USGS further added that the Air Force Technical Applications Center is the only organization in the federal government whose mission is to detect and report technical data from foreign nuclear explosions.

However, experts warned that the detection of a quake does not always indicate a nuclear test.

Earlier last month, on September 23, a magnitude 3.4 earthquake was registered under Mt. Mantap, an area of North Korea where earthquakes do not normally occur.

Later, the Chinese Academy of Sciences and UC Santa Cruz released a joint report that concluded that tunnels in the test site collapsed after the quake.

So far, since October 2006, North Korea has carried out six nuclear tests.